[lubuntu-users] xev output alt(left)

[Harry Putnam]

  Distributor ID: Ubuntu
  Description:      Ubuntu 19.04
  Release:          19.04
  Codename:         disco

  Unicomp keyboard (UNIQ44A) (A starndard layout US keyboard)

  Lubuntu desktop (LXDE)

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Running as vbox guest on an `openindiana (solaris offshoot)' host.
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Using xev from an xterm: When I press `altLeft' in the square input
box I get no response but if I click 'altLeft' repeatedly I eventually
get the following:

  xev output:

  KeyPress event, serial 45, synthetic NO, window 0x4000001,
      root 0x2bd, subw 0x0, time 139977204, (-860,815), root:(627,878),
      state 0x0, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,
      XLookupString gives 0 bytes: 
      XmbLookupString gives 0 bytes:
      XFilterEvent returns: False
  
  KeyRelease event, serial 48, synthetic NO, window 0x4000001,
      root 0x2bd, subw 0x0, time 139977219, (-860,815), root:(627,878),
      state 0x8, keycode 64 (keysym 0xffe9, Alt_L), same_screen YES,
      XLookupString gives 0 bytes:
      XFilterEvent returns: False
  
So apparently `altLeft' only works intermittently and
irregularly. That is, there seems to be no pattern to when it works
and when it does not.

I want that key for use in `xbindkeys' script that I've used for years

`ALT_RIGHT' works reliably but is really awkward to use for me.

Further, using this same setup; (lubuntu guest on 'openindiana' host)
`AltLeft' has worked as expected and reliably until several versions
back. Covering several months ... maybe 4 - 7 mnths.

(Sorry, I made no notes of the exact version or date when the problem
first showed up)

All hardware, plus the version of vbox and of `openindiana' have
remained the same.

Any ideas why `altLeft' only registers a key press  intermittently?